Cinnamaldehyde

• Cinnamaldehyde ( cinnamal )
• Trans-3- phenyl-2- propenal
• (E )-3- phenylprop -2 -en- 1-al
• γ - Phenylacrolein
• FEMA 2286

Yellowish, intensely smelling of cinnamon, oily liquid

Liquid

1.05 g · cm -3 ( 20 ° C)

-8 ° C

251 ° C

<10 Pa ( 20 ° C)

• Insoluble in water (1.1 g · l-1 at 20 ° C)
• Miscible with ethanol, diethyl ether and chloroform

1.6219 (20 ° C)

Attention

2220 mg · kg -1 ( LD50, rat, oral)

Template: Infobox chemical / molecular formula search available

Cinnamaldehyde ( 3-phenyl -2- propenal, FEMA 2286 ) is a yellowish, intensely smelling of cinnamon, oily liquid. He is the main flavoring of cinnamon bark and was first isolated in 1834 from cinnamon oil. Cinnamic aldehyde is an organic chemical compound with the molecular formula C9H8O and counts to the group of phenylpropanoids. It is one of the aromatic compounds and is an α, β - unsaturated aldehyde with a trans -substituted carbon-carbon double bond in the side chain. The isomeric cis- Zimtalaldehyd has little meaning. The information in this article applies only to the trans-cinnamaldehyde.

• 3.1 Physical Properties
• 3.2 Chemical Properties

History and habitat

Cinnamaldehyde was isolated in 1834 by Jean -Baptiste Dumas and Eugène- Melchior Peligot from cinnamon oil and synthesized in 1856 by Luigi Chiozza.

Cinnamaldehyde occurs naturally in cinnamon bark oil ( 42-68 %) and cassia ( to 90 %) before, to a lesser extent but also essential in the leaves of the cinnamon tree and in many other oils.

Representation

Natural sources

Cinnamic aldehyde is obtained by steam distillation from the bark ( lower quality also leaves) of the cinnamon tree.

Technical syntheses

Trans-cinnamaldehyde can be prepared analogously to the cinnamic acid by aldol condensation of benzaldehyde and acetaldehyde in 60 % yield.

The appearance is also achieved by Vilsmeier formylation of styrene in 30 % yield.

The cis- cinnamic aldehyde can be obtained by a photochemical isomerization of the trans-compound:

Properties

Physical Properties

Cinnamaldehyde is a yellowish, intensely smelling of cinnamon, oily liquid, which oxidizes in air gradually to cinnamic acid. It melts at -8 ° C and boils at 251 ° C at atmospheric pressure. It dissolves very poorly in water ( 1.1 g / l at 20 ° C ), but it is miscible with ethanol, diethyl ether and chloroform.

Chemical Properties

Cinnamaldehyde is sensitive to light, heat, alkalies, and certain metals and shows the usual aldehyde and olefin reactions.

It can be reduced to cinnamyl alcohol in 75 % yield by Meerwein Ponndorf - Verley reduction.

By autoxidation in air produced cinnamic acid.

Through stronger oxidants such as potassium permanganate or ozone cinnamic aldehyde is oxidized to benzoic acid.

By hydrogenation of the double bond of hydrocinnamaldehyde formed.

Structural Related

A derivative of coniferyl aldehyde [3 - ( 4-hydroxy -3-methoxyphenyl )-2- propenal ], which additionally have a hydroxyl and at the 3- position carries a methoxy group on the benzene ring at the 4- position, and hence the substitution pattern as has the vanillin.

Use

Cinnamic aldehyde is used as a perfume in the perfume industry in the composition of oriental perfume. It is also used as a fragrance in cosmetics, such as lipsticks, detergents, cleaning agents, toothpaste and mouthwash. Likewise, it is used as a spice in food use.

In its pure form it has sensitizing effects and may cause allergic skin reactions. Patients with a Zimtaldehydallergie often respond well to balsam of Peru, suggesting cross allergies. The compound reacts with nucleophilic structural components of proteins, especially the thiol groups of cysteine ​​and can trigger an immune reaction of the delayed type. Due to its high allergenic potential, he is a part of the so-called " fragrance mix " (English fragrance mix) for patch testing.